Thanks to everyone who got back to me. It looks like we will have critical mass for seminar. See everyone at 3:45.

Sent from my iPhone

On Oct 28, 2020, at 11:36 AM, William Jaco jaco@math.okstate.edu wrote:

 Right now all is good. I can be on.

William H. "Bus" Jaco Regents Professor, Grayce B. Kerr Chair Department of Mathematics

On Tue, Oct 27, 2020 at 9:37 PM Hoffman, Neil <nhoffman@math.okstate.edumailto:nhoffman@math.okstate.edu> wrote: Hello everyone,

Sorry for the two emails.

First, I hope everyone is okay.

With campus closed tomorrow and internet down around Stillwater, I wanted to check in to see if people still could make seminar tomorrow. If we can get a good enough turnout, I am inclined to try to hold seminar tomorrow.

If possible, could you send an email back that you can make seminar tomorrow if it’s held?

I might have to assume that those that don’t respond are without internet, but if you are getting this on your phone because your home internet is down that would be helpful for me to know.

Best, Neil

___________________ Neil Hoffman

On Oct 27, 2020, at 3:31 PM, Hoffman, Neil <neil.r.hoffman@okstate.edumailto:neil.r.hoffman@okstate.edu> wrote:

  Hello everyone,

This week we are really excited to have Roman Aranda (virtually) coming down from Iowa to speak.

His title and abstract are below:

4-manifolds with small trisection genus Speaker: Roman Aranda, University of Iowa Time: Oct 28, 2020, 3:45 PM Room: Virtual meeting https://meet.google.com/frv-bgow-byihttps://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmeet.google.com%2Ffrv-bgow-byi&data=04%7C01%7Cneil.r.hoffman%40okstate.edu%7C077aaef44d6a4eee538208d87b5fab2b%7C2a69c91de8494e34a230cdf8b27e1964%7C0%7C0%7C637394998103933135%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=95Y%2Bu%2B250WYWDWS%2FKxPUMcYXiNCpKTajnzkxfAWj17w%3D&reserved=0

Abstract: In 2016, D. Gay and R. Kirby proved that every closed 4-manifold can be decomposed as the union of three 4-dimensional simple pieces with triple intersection a closed orientable surface of genus g. This decomposition is called a trisection of genus g for M. In 2018, M. Chu and S. Tillmann gave a lower bound for the trisection genus of a closed 4-manifold in terms of the rank of its fundamental group. In this talk, we show that given a group G, there exists a 4-manifold M with fundamental group G with trisection genus achieving Chu-Tillmann’s lower bound. The proof uses techniques of knot theory in simple 3-manifolds.

___________________ Neil Hoffman _______________________________________________ Mdtop mailing list Mdtop@mathdept.okstate.edumailto:Mdtop@mathdept.okstate.edu http://cauchy.math.okstate.edu/cgi-bin/mailman/listinfo/mdtophttps://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fcauchy.math.okstate.edu%2Fcgi-bin%2Fmailman%2Flistinfo%2Fmdtop&data=04%7C01%7Cneil.r.hoffman%40okstate.edu%7C077aaef44d6a4eee538208d87b5fab2b%7C2a69c91de8494e34a230cdf8b27e1964%7C0%7C0%7C637394998103943089%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=TKzhcOciXimrQmtxlLpjHnr1uRtQzHkf6s9xNzjRaZA%3D&reserved=0